that attitude right there is why you never got anything from college/uni. sure, i did the same in many a course/class, but these are not classes i ended up retaining info on. college and uni provides you the atmosphere and the resources to grow and learn upon your own accord. It's not an extension of high school where it's purely the professors job to teach you. That school, at bare minimum, is there to provide you the opportunity to obtain a degree/diploma so you can open doors professionally. They're going to provide you the bare essentials to do that, and at times more than that. But in terms of resources and atmosphere it affords you so much more in learning ability. People get out of college what they put into it. Point blank. If you walked out not gaining anything but a piece of paper, then you didn't put enough effort in. College is not there to make you a smarter or better person, it's there so you can improve yourself, by yourself.
Your want to figure out the system to make it easy, is what fucked you. Sure I've learned a lot myself outside of academia, anyone can. But how structured is that learning process? How detailed does it get? I tend to find that an outside force will challenge someone to dive deeper than they will on their own accord most of the time.